Q. Why do my digital thermometer readings differ?

Answer

There are several factors that influence the body temperature reading that your digital thermometer provides you. It could be that the thermometer was in a hotter or colder room before and you did not bring it to the same ambient temperature as the room you are now taking your measurements in. It could also be that your room temperature is outside the normal operating range of your digital thermometer (10 °C - 40 °C). If you are using a rectal thermometer, variations in either the depth or the angle of insertion of the thermometer probe can throw different readings. Lastly, it is considered normal for your body temperature to actually vary during the day. For example, your body temperature usually runs lower in the mornings than in the evenings, so there is bound to be a difference in readings even when the digital thermometer is perfectly calibrated. However, as a rule, body temperatures should not vary by more than 0.5 °C throughout the day.